In October 1994, Congress took action to protect public safety and national security by enacting the Communications Assistance for Law Enforcement Act of 1994 (CALEA) Pub. L. No. 103-414, 108 Stat. 4279. CALEA further defines the existing statutory obligation of telecommunications carriers to assist law enforcement in executing electronic surveillance pursuant to court order or other lawful authorization. In response to CALEA, the Telecommunications Industry Association produced a standard, referred to as J-STD-25 or J Standard to specify CALEA requirements for telecommunications service providers
In response to CALEA and the J Standard, telecommunications service providers have developed systems that allow surveillance of users. However, one problem with such systems is that they are typically switch based, meaning that the systems are implemented at customer access points, such as end offices or mobile switching centers. One problem with providing surveillance capabilities at a customer access point is that such surveillance capabilities must be provided at every customer access point in a service provider's network in order to be effective. In addition, because access points or switches typically handle non-surveillance calls and surveillance calls, performing surveillance at these nodes can lead to processing bottlenecks and does not provide a scalable solution.
Moreover, some IP-based telephony protocols, such as the session initiation protocol (SIP), may not require an end office. In such protocols, calls may be routed through a softswitch or a feature server. Since softswitchs and feature servers typically handle non-surveillance as well as surveillance calls, like conventional switch-based solutions, performing surveillance at these nodes can lead to processing bottlenecks and does not provide a scalable solution.
Another problem associated with efficiently performing surveillance in today's communications networks is that many different protocols may be used. For example, a call that a government agency desires to monitor may be initiated from a SIP client to an H.323 client. The signaling messages used to set up the call may include both SIP and H.323 messages. Conventional surveillance techniques are typically directed to a signal protocol and are incapable of monitoring messages in multiple protocols for a single call.
Yet another problem associated with conventional surveillance techniques is that there is no ability to identify and optimize the surveillance being performed based on the type of surveillance required by the law enforcement agency. For example, CALEA defines three types of surveillance. These types are pen register surveillance, trap and trace, and interception. Each of these types of surveillance requires different resources in order to be performed. However, conventional switch or call-server-based wire tapping techniques are incapable of automatically distinguishing between the type of surveillance required and optimizing the use of network nodes, such as call servers, based on the surveillance type.
Accordingly, there exists a need for improved methods and systems for intelligent surveillance or users or user equipment in a communications network.